Fortunately, what is the origin of "I came to Shan Wei Gu" and how to understand this sentence?

"Fortunately, I am not alone in the mountains" is the inscription of Mr. Feng Zikai, which was engraved at the request of Mr. Wu Haoran. It means that fortunately I am here, so the mountain is not lonely. In fact, it expresses the loneliness in my heart.

Feng Zikai (Zikai·Feng, November 9, 1898 - September 15, 1975), born in the 24th year of Guangxu, was born in Shimen Town, Tongxiang City, Jiaxing City, Zhejiang Province. His original name was Fengrun, also known as Ren and still, and his nickname was Ji. Later he changed his name to Zikai and his pen name was TK. He is famous for his comics and prose creations that combine Chinese and Western painting techniques. He is a modern Chinese painter, essayist, art educator, music educator, cartoonist, calligrapher and translator.